Musannaf Ibn Abi Shaybah 32133 — From whom the Quran is to be taken

Dawud bin Shabur said that Mujahid said: "I used to take pride among the people in being a firm memoriser of the Qur'an, until I prayed behind Sayyiduna Maslamah bin Mukhallad (may Allah be pleased with him). He began Surah al-Baqarah and did not make a mistake in it, even in an alif or a waw."